I was happy to find this today at a pawn shop and put it on layaway for $320. It appears to have been made in 2003. Looks new cosmetically. Tried it out and everything checked out. I hooked it up to my Ampeg 610hlf there and sounded sooo juicy. They let me crank it... man what a sound! Anyway looking at the back panel I saw that it had a bridge section that read 8ohms only. I tried bridging it using my cab which is 4ohms. Sounded fine. Am I risking blowing something by doing so? Do any of you know why it why this head says to bridge it at a 8ohm only?My experience with bridging other heads is that they can be bridged at 4ohms to combine for maximum power. Any thoughts? Thanks
I absolutely would NOT bridge that amp into 4 ohms. If your WT800 is actually a 2003 amp, it cannot bridge into 4 ohms without overheating and significantly damaging the amp - what is sometimes referred to as "releasing the magic smoke". It could quickly become a very expensive paperweight.
However the 2003 WT800 used banana plugs, not speakon connectors, so that's a bit confusing. The speakon connectors could have been an aftermarket mod as that mod was posted on the Eden forum at one time and it is not particularly difficult to do if you can use a soldering iron. I would presume this was what is known as a WT800A. It will produce 400-watts per channel @ 4 ohms and 800-watts bridged at 8 ohms. My WT500/800 was upgraded to this same power section and supply and I run it bridged into my DNS410 cab.
In mid-July of 2005 Eden released the WT800B which had an upgraded power section. It would go down to 2 ohms per channel and 4 ohms Bridged. That produced 550-watts per channel at 2 ohms and 1100-watts bridged at 4 ohms. The B model did come with speakon connectors but was clearly marked 4 ohm minimum bridged. The WT800B never appeared in an Eden catalog because it came out too late for the 2005 catalog and Eden did not put out a catalog for 2006.
In 2006, the WT800C was released with a few more cooling and circuit protection improvements along with the addition of a backlit Eden logo on the front of the amp. This backlit logo (often referred to as the "porch light") is the easy way to tell if you have the "WT800C" model. Since there was no Eden catalog in 2006, it first appeared in Eden's 2007 catalog. It also was clearly marked 4 ohm minimum bridged on the back of the amp next to the bridged output.
After Marshall bought Eden in December of 2011, they decided they were not comfortable with rating the WT800C at 4 ohms bridged and changed the text to say 8 ohm minimum bridged. Despite the fact that it had been run successfully without problem at 4 ohms bridged for 12 years, they decided to change that ohms text on the back of the amp. They made no changes whatsoever to the amp itself. WT800C amps started appearing with the 8 ohm minimum markings in mid to late 2012. I'm sure it had nothing to do with the new amp series they were working on a the time.
So, I would personally have no problem at all running a WT800C at 4 ohms bridged if the amp has the backlit Eden logo on the front. If a WT800 doesn't have that backlit logo, I would presume that the ohms rating on the back is correct and would NOT run it below 8 ohms.
For more info about your specific amp, I suggest pose your question over at the Edenamps forum along with pictures of the front of your amp while it is powered up and pictures of the rest of the back of the amp (no need to have powered up). There is a fellow by the name of Armin over there who will be able to identify it more clearly. In the meantime, DON'T run it bridged at 4 ohms.